1. Field of the Invention
The invention relates to an appliance for opening and closing a reagent-container stopper in a partially or fully automatic analysis apparatus, and to the method, which is applied by means of this appliance, for opening and closing a reagent-container stopper in a partially or fully automatic analysis appliance.
2. Description of the Related Art
Partially or fully automatic analysis apparatus are in widespread use in medical diagnostics, but also in other fields, for example in analytics. These apparatus essentially comprise three components, a reagent part, a sample part and an analysis part. A certain number of reagents are stored in reagent containers in the reagent part. The reagents must as far as possible be hermetically sealed, in order to prevent contamination and evaporation. A certain number of samples are stored in the sample part. The samples too should also be as far as possible sealed in an airtight manner, possibly for safety reasons, e.g. contamination and potential risk of infection. Furthermore, it is advantageous for the individual compartments, i.e., for example, the entire reagent part or sample part, to be protected against contamination by means of a cover. The necessary transfer of liquids between the individual parts is generally carried out by means of transfer pipettes which, depending on the particular requirements, can move in the X-, Z- and/or Y-direction and/or in the phi-direction (angular rotation). This movement is often driven by stepper motors, in which case one motor is provided for each direction of movement. Owing to the different filling volumes and the different shapes of the reagent and/or sample containers—in the following text reagent and sample containers are referred to generally as reagent containers—the maximum movement in the Z-direction is under certain circumstances extremely great; it may be, for example, from 10 to 200 mm.
These requirements have led to various proposed solutions for the design of reagent-container stoppers. In this context, it is necessary to distinguish between two groups of solutions, on the one hand “passive” systems, in which the reagent-container stopper is designed in such a way that reclosure is to be ensured by the elasticity of the stopper material, as proposed, for example, in EP 0,509,281, and on the other hand “active” systems, in which opening and closing have to take place actively, as described, for example, in EP 0,543,638. However, this document does not provide any description of a possible solution to the question of how the above-described stopper can be opened or closed. The earlier application DE 197 46 169 describes an active reagent-container stopper which is moved by means of a plunger, but this document does not describe any possible way of executing this movement. In practice, the compartment cover presents additional problems. For the reasons listed above, the reagent containers should also only be open at the moment at which the removal is taking place.